examples: make the cube_tex example work on the console

This is a bit primitive, because we are hardcoding the texture stage and
other TEV variables (we'll improve this later), but it does the job.

Author: mardy

examples/sdl2/opengl20/cube_tex.cpp

@@ -35,6 +35,10 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include "textures.h"
 
+#if defined(__wii__) || defined(__gamecube__)
+#include "opengx_shaders.h"
+#endif
+
 #include <SDL.h>
 #include <SDL_opengl.h>
 #include <stdio.h>
@@ -105,6 +109,10 @@ process_event(SDL_Event *event)
 
 int main(int argc, char **argv)
 {
+#if defined(__wii__) || defined(__gamecube__)
+    setup_opengx_shaders();
+#endif
+
     if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_JOYSTICK) != 0) {
         SDL_Log("SDL init error: %s", SDL_GetError());
         return EXIT_FAILURE;

examples/sdl2/opengl20/opengx_shaders.c

@@ -67,6 +67,46 @@ static void gl2gears_setup_draw(GLuint program, const OgxDrawData *draw_data,
     GX_SetTevOp(GX_TEVSTAGE0, GX_PASSCLR);
 }
 
+typedef struct {
+    GLint mvp_loc;
+    GLint tex_sampler_loc;
+} CubeTexData;
+
+static void cube_tex_setup_draw(GLuint program, const OgxDrawData *draw_data,
+                                void *user_data)
+{
+    CubeTexData *data = user_data;
+    float m[16];
+    glGetUniformfv(program, data->mvp_loc, m);
+    GLint texture_unit;
+    glGetUniformiv(program, data->tex_sampler_loc, &texture_unit);
+    ogx_set_mvp_matrix(m);
+
+    uint8_t tex_map = GX_TEXMAP0;
+    uint8_t tex_coord = GX_TEXCOORD0;
+    uint8_t input_coordinates = GX_TG_TEX0;
+    uint8_t stage = GX_TEVSTAGE0;
+    GXTexObj *texture;
+    texture = ogx_shader_get_texobj(texture_unit);
+    GX_LoadTexObj(texture, tex_map);
+    GX_SetNumChans(1);
+    GX_SetChanCtrl(GX_COLOR0A0, GX_DISABLE, GX_SRC_REG, GX_SRC_VTX,
+                   0, GX_DF_CLAMP, GX_AF_NONE);
+
+    // In data: c: Texture Color b: raster value, Operation: b*c
+    GX_SetTevColorIn(stage, GX_CC_ZERO, GX_CC_RASC, GX_CC_TEXC, GX_CC_CPREV);
+    GX_SetTevAlphaIn(stage, GX_CA_ZERO, GX_CA_RASA, GX_CA_TEXA, GX_CA_APREV);
+    GX_SetTevColorOp(stage, GX_TEV_ADD, GX_TB_ZERO, GX_CS_SCALE_1, GX_TRUE,
+                     GX_TEVPREV);
+    GX_SetTevAlphaOp(stage, GX_TEV_ADD, GX_TB_ZERO, GX_CS_SCALE_1, GX_TRUE,
+                     GX_TEVPREV);
+    GX_SetTexCoordGen(tex_coord, GX_TG_MTX2x4, input_coordinates, GX_IDENTITY);
+
+    GX_SetNumTevStages(1);
+    GX_SetTevOrder(stage, tex_coord, tex_map, GX_COLOR0A0);
+    GX_SetNumTexGens(1);
+}
+
 static bool shader_compile(GLuint shader)
 {
     uint32_t source_hash = ogx_shader_get_source_hash(shader);
@@ -82,6 +122,15 @@ static bool shader_compile(GLuint shader)
         ogx_shader_add_attributes(shader, 2,
                                   "position", GL_FLOAT_VEC3, GX_VA_POS,
                                   "normal", GL_FLOAT_VEC3, GX_VA_NRM);
+    } else if (source_hash == 0x53560768) {
+        /* cube_tex.cpp vertex shader */
+        ogx_shader_add_uniforms(shader, 2,
+            "MVP", GL_FLOAT_MAT4,
+            "myTextureSampler", GL_SAMPLER_2D);
+        ogx_shader_add_attributes(shader, 3,
+            "vertexPosition_modelspace", GL_FLOAT_VEC3, GX_VA_POS,
+            "vertexUV", GL_FLOAT_VEC2, GX_VA_TEX0,
+            "vertexColor", GL_FLOAT_VEC4, GX_VA_CLR0);
     }
 }
 
@@ -99,11 +148,18 @@ static GLenum link_program(GLuint program)
         data->light_pos_loc = glGetUniformLocation(program, "LightSourcePosition");
         ogx_shader_program_set_user_data(program, data, free);
         ogx_shader_program_set_setup_draw_cb(program, gl2gears_setup_draw);
+    } else if (vertex_shader_hash == 0x53560768) {
+        /* cube_tex.cpp vertex shader */
+        CubeTexData *data = calloc(1, sizeof(CubeTexData));
+        data->mvp_loc = glGetUniformLocation(program, "MVP");
+        data->tex_sampler_loc = glGetUniformLocation(program, "myTextureSampler");
+        ogx_shader_program_set_user_data(program, data, free);
+        ogx_shader_program_set_setup_draw_cb(program, cube_tex_setup_draw);
     }
     return GL_NO_ERROR;
 }
 
-const OgxProgramProcessor s_processor = {
+static const OgxProgramProcessor s_processor = {
     .compile_shader = shader_compile,
     .link_program = link_program,
 };

examples/sdl2/opengl20/opengx_shaders.h

@@ -0,0 +1,42 @@
+/*****************************************************************************
+Copyright (c) 2024  Alberto Mardegan ([email protected])
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+3. Neither the name of copyright holders nor the names of its
+   contributors may be used to endorse or promote products derived
+   from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL COPYRIGHT HOLDERS OR CONTRIBUTORS
+BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+*****************************************************************************/
+
+#ifndef OPENGX_SHADERS_H
+#define OPENGX_SHADERS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void setup_opengx_shaders(void);
+
+#ifdef __cplusplus
+} // extern C
+#endif
+
+#endif /* OPENGX_SHADERS_H */