add depth support

Author: HeliumAnt

Source/Renderer/RenderTarget.cpp

@@ -4,6 +4,7 @@
 #include "GLCheck.h"
 #include "raylib/rlgl.h"
 #include "WindowMan.h"
+#include "Constants.h"
 
 #include "glm/glm.hpp"
 #include "glm/gtc/matrix_transform.hpp"
@@ -63,7 +64,7 @@ void RenderTarget::Begin(bool clear) {
 
 	rlMatrixMode(RL_PROJECTION);
 	rlLoadIdentity();
-	rlOrtho(0.0f, m_Size.w, m_Size.h, 0.0f, -1.0f, 1.0f);
+	rlOrtho(0.0f, m_Size.w, m_Size.h, 0.0f, c_NearDepth, c_FarDepth);
 	rlMatrixMode(RL_MODELVIEW);
 	rlLoadIdentity();
 

Source/Renderer/raylib/rlgl.c

@@ -740,16 +740,20 @@ void rlVertex3f(float x, float y, float z)
     RLGL.currentBatch->draws[RLGL.currentBatch->drawCounter - 1].vertexCount++;
 }
 
+void rlZDepth(float z) {
+    RLGL.currentBatch->currentZ = z;
+}
+
 // Define one vertex (position)
 void rlVertex2f(float x, float y)
 {
-    rlVertex3f(x, y, RLGL.currentBatch->currentDepth);
+    rlVertex3f(x, y, RLGL.currentBatch->currentDepth - RLGL.currentBatch->currentZ);
 }
 
 // Define one vertex (position)
 void rlVertex2i(int x, int y)
 {
-    rlVertex3f((float)x, (float)y, RLGL.currentBatch->currentDepth);
+    rlVertex3f((float)x, (float)y, RLGL.currentBatch->currentDepth - RLGL.currentBatch->currentZ);
 }
 
 // Define one vertex (texture coordinate)

Source/Renderer/raylib/rlgl.h

@@ -423,6 +423,7 @@ typedef struct rlRenderBatch {
     rlDrawCall *draws;          // Draw calls array, depends on textureId
     int drawCounter;            // Draw calls counter
     float currentDepth;         // Current depth value for next draw
+    float currentZ;             // Current z order added to depth.
 } rlRenderBatch;
 
 // OpenGL version
@@ -629,6 +630,7 @@ RLAPI void rlNormal3f(float x, float y, float z);       // Define one vertex (no
 RLAPI void rlColor4ub(unsigned char r, unsigned char g, unsigned char b, unsigned char a); // Define one vertex (color) - 4 byte
 RLAPI void rlColor3f(float x, float y, float z);        // Define one vertex (color) - 3 float
 RLAPI void rlColor4f(float x, float y, float z, float w); // Define one vertex (color) - 4 float
+RLAPI void rlZDepth(float z);                           // Set current draw depth for Vertex2(i,f).
 
 //------------------------------------------------------------------------------------
 // Functions Declaration - OpenGL style functions (common to 1.1, 3.3+, ES2)

Source/System/Constants.h

@@ -142,6 +142,14 @@ namespace RTE {
 	    1.0f, -1.0f, 1.0f, 1.0f,
 	    -1.0f, 1.0f, 0.0f, 0.0f,
 	    -1.0f, -1.0f, 0.0f, 1.0f};
+
+	static constexpr float c_GuiDepth = -100.0f;
+	static constexpr float c_DefaultDrawDepth = 0.0f;
+	static constexpr float c_TerrainBGDepth = 50.0f;
+	static constexpr float c_BackgroundDepth = 100.0f;
+
+	static constexpr float c_FarDepth = 200.0f;
+	static constexpr float c_NearDepth = -200.0f;
 #pragma endregion
 
 #pragma region Math Constants