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我想實現一個簡單的rendermanager。另一個類提供了表示四元組的結構,並將其複製到呈現管理器中的頂點數組緩衝區中。指針和opengl繪圖問題
但是,複製似乎並沒有工作,當我手動創建一個結構並複製到vertexarray一切都很好,它呈現。但在複製的某個地方,一切都會出錯。我可以看到使用gdb(值不同),但我無法弄清楚發生了什麼。
RenderManager方法
-(id)init
{
if([super init]){
iva = calloc(MAX_QUADS, sizeof(quad));
quad draw = {
0.0f,0.0f,0.0f, 0.0f,0.0f,1.0f, //Bottom left
1.0f,0.0f,0.0f, 0.0f,0.0f,1.0f, //Top Left
1.0f,1.0f,0.0f, 0.0f,0.0f,1.0f, //Top Right
0.0f,1.0f,0.0f, 0.0f,0.0f,1.0f, //Bottom Right
0.5f,0.5f,0.0f, 0.0f,0.0f,1.0f, //Center
};
如果我評論了這一點,沒有平局。使用它,我得到了很好的四我期待
memcpy(iva, &draw, sizeof(draw));
. . . OpenGl methods
//Add the quad details to the render queue
-(void)addDetailsToRenderQueue:(quad *)details
{
if(iva == NULL)
NSLog(@"Error claiming memory, something is very wrong");
if(renderCount + 1 > MAX_QUADS){
NSLog(@"Render buffer full, dumping...");
[self render];
}
memcpy((quad *)iva + renderCount++, &details, sizeof(quad));
}
//Render the details in the render queue, for each quad we need to make two triangles.
-(void)render
{
int counter = 0;
renderCount *= 5;
for(int i;i < renderCount;){
ivaIndices[counter++] = i + 0; // Bottom left
ivaIndices[counter++] = i + 1; //Top Left
ivaIndices[counter++] = i + 4; //Center
ivaIndices[counter++] = i + 1; //Top Left
ivaIndices[counter++] = i + 2; //Top right
ivaIndices[counter++] = i + 4; //Center
ivaIndices[counter++] = i + 2; //Top right
ivaIndices[counter++] = i + 3; //Bottom right
ivaIndices[counter++] = i + 4; //Center
ivaIndices[counter++] = i + 3; //Bottom right
ivaIndices[counter++] = i + 0; //Bottom Left
ivaIndices[counter++] = i + 4; //Center
i += 5;
}
glBindVertexArrayOES(_vertexArray);
glDrawElements(GL_LINE_STRIP,12, GL_UNSIGNED_SHORT, ivaIndices);
// Reset the number of quads which need to be rendered
renderCount = 0;
}
片管理方法
@interface TileSet : NSObject
{
quad *tiles;
NSUInteger tileCount;
RenderManager *sharedRenderManager;
}
-(id)init
{
if([super init]){
tiles = calloc(MAX_HEIGHT * MAX_WIDTH, sizeof(quad));
tileCount = 0;
sharedRenderManager = [RenderManager sharedManager];
}
[self fillArray];
return self;
}
-(void)fillArray
{
int rows = 4;
int columns = 12;
for(int i = 0; i < rows;i += 2) {
for(int j = 0;j < columns;j += 2) {
quad tmp;
tmp.v1.x = i;
tmp.v1.y = j;
tmp.v1.z = 0.0f;
tmp.v1.nx = 0.0f;
tmp.v1.ny = 0.0f;
tmp.v1.nz = 1.0f;
tmp.v2.x = i + 1;
tmp.v2.y = j;
tmp.v2.z = 0.0f;
tmp.v2.nx = 0.0f;
tmp.v2.ny = 0.0f;
tmp.v2.nz = 1.0f;
tmp.v3.x = i;
tmp.v3.y = j+1;
tmp.v3.z = 0.0f;
tmp.v3.nx = 0.0f;
tmp.v3.ny = 0.0f;
tmp.v3.nz = 1.0f;
tmp.v4.x = i + 1;
tmp.v4.y = j+1;
tmp.v4.z = 0.0f;
tmp.v4.nx = 0.0f;
tmp.v4.ny = 0.0f;
tmp.v4.nz = 1.0f;
tmp.v5.x = i + 0.5;
tmp.v5.y = j + 0.5;
tmp.v5.z = 0.0f;
tmp.v5.nx = 0.0f;
tmp.v5.ny = 0.0f;
tmp.v5.nz = 1.0f;
memcpy((quad *)tiles + (i*j + j), &tmp, sizeof(quad));
tileCount++;
}
}
}
//Draw the tiles in the tileset, loop through and add to renderManagers queue
-(void)render
{
for(int i = 0; i < tileCount;i++)
[sharedRenderManager addDetailsToRenderQueue:&tiles[0]];
}
編輯 在答覆問題,添加
NSLog(@"Tiles:%x\tDisgusting pointer math:%x",tiles,(quad *)tiles + (i*j + j));
給的結果
2011-10-21 21:29:21.456 TerrainRendering[11293:fb03] Tiles:7316200 Disgusting pointer math:7316200
2011-10-21 21:29:21.458 TerrainRendering[11293:fb03] Tiles:7316200 Disgusting pointer math:73162f0
2011-10-21 21:29:21.463 TerrainRendering[11293:fb03] Tiles:7316200 Disgusting pointer math:73163e0
2011-10-21 21:29:21.464 TerrainRendering[11293:fb03] Tiles:7316200 Disgusting pointer math:73164d0
2011-10-21 21:29:21.465 TerrainRendering[11293:fb03] Tiles:7316200 Disgusting pointer math:73165c0
2011-10-21 21:29:21.465 TerrainRendering[11293:fb03] Tiles:7316200 Disgusting pointer math:7316200
2011-10-21 21:29:21.466 TerrainRendering[11293:fb03] Tiles:7316200 Disgusting pointer math:73164d0
2011-10-21 21:29:21.467 TerrainRendering[11293:fb03] Tiles:7316200 Disgusting pointer math:73167a0
2011-10-21 21:29:21.470 TerrainRendering[11293:fb03] Tiles:7316200 Disgusting pointer math:7316a70
2011-10-21 21:29:21.470 TerrainRendering[11293:fb03] Tiles:7316200 Disgusting pointer math:7316d40
的NSLog(@ 「%X%X」,...)tiles'的''(四*)瓷磚的地址和+(I * J + j)的',我覺得計算出的地址不是您所期望的。 –
現在那個指針值是你期望的那個值嗎?或者它應該是什麼? –
老實說我不是很確定我在期待什麼。似乎不正確。 – botptr